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Hi, everyone! And welcome back to geek time. Hi, Brad.

Hey! How's it going Lulu?

Yeah! Not doing too bad! What are we going to talk about today？

We're going to talk about 3D printing. Lately I busted up my 3D printer and I wanted to make some parts for my camera basically just connecting parts to add on things like the microphone or connect it to a stand.

3D printing, I start to feel like every technology that we talk about you have parts of it or already have it at home.

Well, you know, I'm a technological kind of geek, if I see it, I want to buy it.

That sounds very cool. So let's talk about 3D printing or 3D printers, 3D打印. I still remember watching the Big Bang Theory and I think a lot of our audience if you watch that show, you remember that Leonard and Howard, they were playing with a 3D printer. And the first time I saw it, I thought this is so cool, but also this is so pointless, because they were printing things, like 1 to 1 ratio, they were printing things that already exist in life and you are thinking what is the point? But so let's start with what is 3D printing.

In most cases, 3D printing is just designing a shape like a software, kind of a CAT software, comp

So as the name suggests, you print something that is 3D.

Yeah. The way it works is typically you have plastic, most things are printed with plastics, and you just go layer by layer by layer and you can print them at different like thicknesses, but the thinner each layer is, the more definition you kind of have in it，you can make it look kind of more globy if you have a really t it'll be faster. But …

I know this is all matter of fact to you, but for me I’m just trying to wrap my head around how you can put in plastic. And then all of these letters get on the paper because it's been printed on with ink, do you just feed plastic into the printer？

So basically, you have a, it’s almost like a string of plastic. You have a really long string almost like thread for making like sewing. You feed that into a machine. It heats it up. And then once it hits a particular temperature, it can come out as liquid. And then it shaped really, it's like put down in really thin layer. And then once you put down a layer, it cools off a little bit and it becomes hard.

所以塑料要液化, and then you build it that way. I see, let's say if we print a cube, inside it, is it empty or is it solid?

It's neither empty nor solid. You can have different shapes, but you have to have some sort of like a webbing on the inside, you have to have some sort of structure on the inside. If you don't have anything, then when you try to print the top of the cube, it'll just like collapse, you have to just print downwards. And so what you do is you print the bottom layer which is completely solid, then as you print up, the outer like the side of the cube is solid, but the inside will have like a lattice structure.

Like a support structure. It's almost like a scaffolding像建楼的时候支架一样. I see. What about the structure after you are done. is it's kept inside?

It's kept inside. Right. But uh if depending upon how the shape is, like with a cube, the cube has a shape, but it doesn't like flow over. Whereas if you have like a sphere, the bottom layer is really tiny, right. But then as you go up to the middle part of the middle part of the sphere, you kind of have this overhang where there's almost nothing beneath it.

I see.

And so you kind of have to print something to support that while you're making a sphere. But usually the way they do this is they print kind of like a piece that will just easily break off.

I see. So, it depends on the shape. One other thing from just like an ordinary person, if I want to buy 3D printer like you did. Is it very expensive because I’ve heard the printer itself is not that expensive, but the materials are very expensive?

It depends on what materials you use. My printer only cost me about $200.

Really? that Cheap.

It did require some assembly but you could go on YouTube and it would show you like which part to use which screw to use. You could watch the whole video if you didn't want to like look at the instructions, but you could watch just how it's built. but like…

OK, I’m out. I won't be able to do to make a DIY 3D printer.

It's not that difficult actually. But if you didn't want to do that, you can buy 3D printers that are fully assembled and ready to go out of the box, whereabout $500 or $600 and up.

That's still very doable. What about the materials?

The materials you can buy the strands of plastic like I bought one recently here for it was like a kilogram, yeah, about a kilogram of material for about 80 RMB. So it's not very expensive.

But what is the concept of one kilogram就是一公斤？What can you print？

You can print a lot of things, like I printed the entire body of my quadcopter…

Your Drone?

Yeah, for my drone, for less than half a kilogram, less than half I would say.

所以无人机Brad也是用这个打出来的. And is plastic, the only material they use in 3D printer?

Our using 3D printer for most consumer grades, you're gonna use plastics only. There's a few other ones. But if you go for things that are a bit more expensive like thousands of dollars like really expensive printers, you can get printers that actually print with metal. They don't heat up the metal like the 3D printer does. What they do is they throw a layer of metal dust and then they heat up the specific areas they want to print, and then they blow away the rest of the material, and then they reset another layer of dust on there.

So for plastic is liquid and for metals are this dust.

It's a dust and then they turn into a liquid and then it’s set.

This is starting to mess with plastics and metals. Any other material？

This is a bit of the weird science aspect, but biological materials.

Biological生物材料liked what？Skin flesh.

I haven't seen skin flesh specifically yet, but I have seen like a muscle tissue for like making a 3D printed heart. I don't think they've actually used it in a person yet, but they are…

That’s the direction.

Yeah, that's the direction, basically what they did was they took kind of like a shape of a heart, and they added like all the ventricles, like the tubes, and everything inside of the heart. Then they used a 3D printer to kind of fill in using like cellular material that would be used for making like muscle tissue and allow it to develop into that.

肌肉组织打印出来的心脏. That is fascinating. But 3D printer it does have its limitation with all of these fascinating things that can do. 3D printing does sound like it has its limitation. For example, a lot of these printers I’ve seen they're not very big.

Right, most of the 3D printers that you buy for that you can use in your home are going to have kind of a limitation of like a 20-to-30-centimeter cube, so it can be a cube usually about that size.

Not a lot you can print with this

Not a lot. but usually, what people do is I’ll design something, then they'll print it in parts. So like for my quadcopter, like I had my central body and then I would print like an arm, and that goes off from the central body.

And then you assemble.

Yeah, then you just use like different types of screws or bolts to connect everything together. Sometimes people just have like, they kind of make it like one of the old Japanese houses where it's kind of like wooden pegs kind of thing or they have the material, or they just kind of like build kind of like a way where it can connect, just adding like some super glue or something。

Yeah, that is something that I wanted to ask. I would imagine they use it a lot in architectural world. They can use this to make models.

They actually can build houses with a 3D printer.

I don't know if I want to live in a house that's built using the materials that are from a 3D printer.

It's basically the way it works. It's a 3D printed concrete. So it structurally sound just like a regular concrete brick. But they print it into the shape of a house.

So the material is still concrete. OK, I see, because I am not going to live in a plastic house.

With using this, they basically have a house designer, a very minimally stick type house design with like bedrooms and everything. You bring in the printer and you set it to print. And basically, what it'll do is it like print the first layer and after it prints the first layer, then you have a few workers come in, and they put in like a little bit of wiring, because it sets specifically in a layer, so they can go in put in the set of wires and pipes and stuff, and it makes it very fast and efficient. And then once they finish, they can move to the next house and the 3D printer just goes to the next layer.

I see. One last question before we wrap up this basic episode. When you are printing these things, what kind of information do you feed into the printer? Do you have to have, let's say, a picture or do you have to have like a 3D breakdown of the design structural design. 是要给什么信息给到3D打印机，它才能打印出来这种东西。

You can use a printing software. You have like, there's a bunch of free ones like Tinker CAT or free CAT, you just go online, you download the program, and it gives you shapes, and then you can build something using those shapes or you can specifically go in there and, just go to the my new level and design a line, connect that to another shape, design everything piece by piece. And then once you have a 3D shape. You use another program which basically fills in the space in between. So it's called Slicer program. It takes a 3D shape and then cuts it into all the layers and then anything that's empty, it will fill in with scaffolding. Yeah.

I'm saying I see, but I am only just about grasping what you are talking about. That is pretty hard core for basic episode, I don't know what we're gonna talk about in advanced episode, but I’m sure I’m looking forward to it. Those of you who are listening to our show, actually, there are engineers listening to our show. If you have played with 3D printers or if you are currently using one, let us know what you think. And also, for those of you who haven't used it like me, what would you want to print? If you can get your hands on a 3D printer.

The sky is the limit almost.

Thank you Brad for coming to the show. We’ll see you next time, everyone. Bye!